The principal cause, according to animal welfare groups and veterinary scientists, is that the native grasses which are the wombats' staple food have been pushed out by exotic plants such as onion and potato weed. The situation, created by poor land management, has been exacerbated by two years of above average rainfall during which the weeds have flourished. Not only do the weeds provide scant nutrition, but many of them are toxic and can cause liver disease.
One of three species of wombat, the southern variety is found in the grassy plains and open woodland of southern Australia. The wombats live mainly underground and usually put on most of their fat supplies in winter and spring, when food is more plentiful, enabling them to survive the summer.
They live principally, though, on farming properties that have been over-grazed by sheep and cattle in the past and recently de-stocked. "That has led to an imbalance in the eco-system, with the loss of native plants and overgrowth of weeds," Dr Lucy Woolford, a veterinary pathologist at Adelaide University, said.
The southern hairy-nosed wombat is still well off compared with the northern species, which crashed to a low of just 35 individuals in the 1980s. Intensive conservation efforts including IVF techniques to boost their fertility and building a predator-proof fence around their sole remaining colony, in central Queensland, have boosted their numbers to 138.
No one is sure how many southern wombats are left. No survey has been conducted since 1989.
- Independent